Chaeles s



. EFENJP'FJ .oC: COMPOSITIONS,

COATING OR PLASTIC.

UNITED STATES oHAELEs s. LooKwooD, or ALBANY, NEW YORK, AND JOHN W. HYYATT,

OF NEWARK, NEW JERSEY, ASSIGNORS TO THE BONSILATE ooMPANY,

(LIMITED,) or LBANY, N. Y.

PROCESS OF TREATING SILICATE F SODA IN COMBINATION WITH ZINC OXIDE, &c.

EPECIFICATIQN forming part ,of Letters Patent No. 317,388, dated May 5, 1885.

Application filed August 13, 1884. (No specimens.)

- To all whom it may concern:

Be it known that we, CHARLEs S. LOCK- WOOD, a citizen of the United States, and a resident of Albany, in the county of Albany and State of New York, and J OHN W. HYATT, a citizen of the United- States, residing at Newark, Essex county, New Jersey, have invented' a certain new and useful Improved Process of Treating Silicate of Soda in combination with Zinc Oxide and the Composition Produced by'such Process, of which the following is a specification.

The invention has relation to an improved process of treating silicate of soda in combina- 1 tion with zinc oxide and to the composition produced by such process, as hereinafter set forth. We take silicate of soda which is made into a solution, a suiiiclent quantity of water being added to enable a thorough filtration. This solution we reduce to such an extent that at atemperature of 60 it has a specific gravity of about 26 Baum. Of the solution of silicate of soda in the condition just stated we take, say, eight pounds, to which we add, say, two pounds of white zinc oxide and mix the two as effectually as e. c then place the mixture, preferably, on a waterbath and arate it slowly until a sufficient part of iv as been removed to allow the ma- 0 terial to be comminuted. Before the comminution is attempted the compound will be allowed to cool, and will then be round to a fine ower by means of a mill om T 1n, or reduced in any other way. It is 3 5 essential that great care be taken not to carry the evaporation too far. To ascertain whether the powder is in a proper condition to be subjected to the action of the mold, we have been accustomed to press it 'upon a 40 heated surface of polished metal. If it is in such a condition that it will not adhere to the metal surface when subjected to the degree of heat and pressure required to weld it, (say a temperature of about 300 Fahrenheit and a 5 pressure of, say, eight thousand pounds to the square inch,) the proper degree of desiccation will have been reached. The material, having been brought to a condition in which it is W'Wf ready to be subjected to heat and pressure, is introduced into molds of ordinary construc- 0 tion and pressed to form the desired article. The dies employed are" of usual construction. They will be heated to a temperature of, say, 259 to 350 Farhenheit, or thereabout, and

the material will be subjected to a pressure of about, say, eight thousand pounds to the square inch, more or less, according to the character of the article, the heat and pressure being continued until a complete consolidation of the contents of the mold has been effected.

One of the chief difficulties connected with the utilization of alkaline silicates in the production of articles of commerce has been that aft-er the article is completed it attracts moisture and has a'tendency to effloresce to such an extent as to destroy its value. To correct these difliculties is one of the principal objects of our process, and it is accomplished by the use of a bath of an1moniacalsalts,in which the I material is introduced after it is subjected to to the action of the molds.

In practice we prefer to immerse the completed article in the bath after it has been moulded and polished.

Having proceeded in the formation of the ararticle, as hereinbefore described,it is polished in any convenient way and then introduced into a bath consisting of, say, two parts of water to'one part of chloride of ammonium 1n 8o "mob it is permitmm ten to fifteen hours, or until a test shows that there is no furtherv alkaline reaction. Any of the ammoniacal salts may be made use of, and the strength of the bath will be varied according What we claim as our invention, and de- 5 sire to secure by Letters Patent, is-

1. The within-described process of forming articles of silicate of soda and oxide of zinc,

which consists in, first, forming an aqueous solution of the silicate of soda with an admixture of zinc oxide in the proportion of about four parts of silicate (26 Baum) to one part of zinc oxide; second, desiccating and comminuting the compound, and, third, subjecting the desiccated powder to pressure in heated molds, and, fourth; treating the article in an ammouiacal bath, substantially as set forth.

2. The use of an ammouiacal bath for the V purpose of correcting the tendency of an alkaline silicate to attract moisture and to efiioresce, substantially as set forth.

3. The within-described process of forming articles of silicate of soda and oxide of zinc, which consists in, first, forming auaqueous solution of the silicate of soda with an a'dmix-' ture of zinc oxide in the proportion of about four parts of silicate (26 Baum)'to one part of zinc oxide, and,second,desiccating the compound,- comminuting it, and subjecting 'it to treatment in an ammouiacal bath, substan- 2 5 tially asset forth.

CHAS. S. LOCKWOOD. Witnesses:

ROBERT C. PRUYN, E. A. GROESBECK. Signed at Newark, in the county of Essex and State or New Jersey, this 9th day of August, A. D. 1884. 7

'JOHN'W.'HYATT.

- 'Witnesses:

- "ABRAHAM MANNERs,

Urns. 0. GILL. 

